GENEVA, September 13 (UNHCR) - The UN refugee agency said Friday that the number of Syrians risking dangerous and irregular boat trips to reach southern Italy has risen sharply in recent weeks.

"Over the past 40 days, [some] 3,300 Syrians, of whom more than 230 were unaccompanied children, have come ashore - mainly in Sicily. Some 670 of these arrivals were during the past week," UNHCR spokesman Adrian Edwards told journalists in Geneva.

He said that more than 30 boatloads of people have been involved. The majority have come from Egypt, although some started their journeys from Turkey. "Most of the arrivals have been families with children," he said, adding that "several people have needed hospital treatment for dehydration, and there have been instances of people having to be airlifted directly from the boat they were travelling on."

The spokesman said that a nurse from Damascus died as she crossed last week with her husband and children. Her husband gave permission for her liver and kidneys to be used for three patients in Italy seeking organ transplants.

UNHCR estimates that more than 4,600 Syrians have arrived in Italy by sea since the beginning of 2013. About two thirds of these arrivals have been in August.

Edwards said that most of the Syrians that UNHCR had spoken to said they came from Damascus, with many being Palestinian refugees born in Syria. On arrival, people are taken to reception centres. In recent months many Syrians have moved on from countries at the European Union's external borders to other parts of Europe.

According to the latest UNHCR figures, almost 21,900 people have arrived so far in southern Italy this year. This is a significant increase on levels in 2012, when a total 7,981 people arrived. The main nationalities have been Eritreans 5,778 (594 in 2012), Somalis 2,571 (1,280 in 2012) and now Syrians 3,970 (369 in 2012).